Systems and methods for obstruction detection on a luminaire optics

ABSTRACT

A lighting device includes an optical assembly and an obstruction sensor configured to receive radiation reflected by the optical assembly. The lighting device also includes a processor that is configured to receive information corresponding to the radiation reflected by the optical assembly from the obstruction sensor, and compare the received information to a plurality of known reflection patterns associated with one or more properties of the optical assembly to determine a property of the optical assembly.

RELATED APPLICATIONS AND CLAIM OF PRIORITY

This application claims priority to and is a continuation of U.S. patentapplication Ser. No. 16/525,910, filed Jul. 30, 2019, the disclosure ofwhich is hereby incorporated by reference in its entirety.

BACKGROUND

The advent of light emitting diode (LED) based luminaires has providedsports arenas, stadiums, other entertainment facilities, and othercommercial and industrial facilities the ability to achieve instanton-off capabilities, intelligent controls and adjustability whiledelivering excellent light quality, consistent light output, andimproved energy efficiency. Because of this, users continue to seekimprovements in LED lighting devices. The condition or optical qualityof an optics (e.g., lens, optical cover, reflector, etc.) of a luminairemay impede the light output and the operation of the luminaire.

For example, accumulation of dirt and debris, water, frost, or otherelements on the optics of the luminaire may lead to undesirable changesin the light output of the luminaire and/or may cause damage to theluminaire itself. For example, accumulation of dirt and debris on aluminaire optics may lead to an increase in the inside temperature ofthe luminaire which cannot be removed by a heat sink effectively, anddamage may occur if the inside temperature of the luminaire increasesover a temperature threshold. Examples of such damage may includeyellowing of the optics, cracking, deformation, or the like.

Maintenance operations on luminaire equipment may occur before damageoccurs (i.e., preventive maintenance) or after damage occurs (i.e.,repair and/or replacement maintenance). It is more costly to repair adamaged luminaire than to perform preventive maintenance, whereasreplacement of the whole unit comes at an even greater cost to includeloss of use of the luminaire equipment while replacement parts aredelivered. It is, therefore, desirable to discover problems (e.g.,detection of obstruction of the luminaire optics) before they can causedamage.

This document describes a lighting fixture and methods of manufacturingthereof that are directed to solving the issues described above, and/orother problems.

SUMMARY

In one or more scenarios, a lighting device may include an opticalassembly and an obstruction sensor configured to receive radiationreflected by the optical assembly. The lighting device also includes aprocessor and non-transitory computer readable medium that includesprogramming instructions. The processor is configured to receiveinformation corresponding to the radiation reflected by the opticalassembly from the obstruction sensor, and compare the receivedinformation to a plurality of known reflection patterns associated withone or more properties of the optical assembly to determine a propertyof the optical assembly.

Optionally, the obstruction sensor may also be configured to transmitradiation towards the optical assembly. In some embodiments, theobstruction sensor may be mounted in the lighting device in a locationthat allows radiation transmitted by the obstruction sensor to be atleast partially reflected by an optical element of the optical assembly(for example, the substrate).

Optionally, the obstruction sensor may include and infrared (IR) sensorand the reflected radiation may include IR radiation.

In some embodiments, the property may be an obstruction or a deformity.The processor may further be configured to analyze the receivedinformation to determine the presence of at least a threshold level ofan obstruction or a deformity on the optical assembly, and in responseto determining the presence of at least the threshold level of theobstruction or the deformity on the optical assembly, perform arestorative action. The restorative action may provide an alert to auser. The alert may be instructions to repair the obstruction or thedeformity, instructions to control power delivered to a light source ofthe lighting device, or information relating to the obstruction or thedeformity. The programming instructions to control the power deliveredto the light source may include instructions to reduce power deliveredto the light source while maintaining a constant illumination output bythe lighting device. Optionally, the restorative action may controlpower delivered to the light source. The programming instructions mayalso be designed to cause the processor to analyze the receivedinformation to determine a rate of conditions of the optical assembly,to analyze the rate of change of conditions to determine whether thelighting module includes a problem, and to provide an alert to a user,wherein the alert includes information about the problem. Accumulationof debris, dirt, liquid, moisture, or foreign materials on an inside oran outside of the optical assembly are types of obstructions ordeformities. Likewise, changes in color, change in shape, breakage, orformation of pits are also types of obstructions or deformities. Thethreshold level may be determined based on the type of light source, theoptical assembly material, a material of other components of thelighting module, one or more ambient conditions, a type of use of thelighting module, or efficiency of a heat sink associated with thelighting module. The programming instructions may further be designed tocause the processor to analyze the received information to determine atype of obstruction or deformity, a level of obstruction or deformity,or a location of obstruction or deformity on the optical assembly.

Alternatively, in another embodiment, an obstruction sensor may sensereal-time conditions of an optical assembly of a lighting device. Theobstruction sensor may include a transceiver configured to transmitradiation towards the optical assembly and receive radiation reflectedby the optical assembly. The reflected radiation may be indicative ofone or more conditions of the optical assembly.

In an embodiment, a method for determining a property of an opticalassembly of a lighting device may include receiving informationcorresponding to radiation reflected by the optical assembly from anobstruction detection sensor mounted inside the lighting device, andcomparing the received information to a plurality of known reflectionpatterns associated with one or more properties of the optical assemblyto determine the property of the optical assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an example lighting device,according to an embodiment.

FIG. 2 illustrates a top view of an example lighting module, accordingto an embodiment.

FIG. 3 is a cross-sectional view along cutline 3-3 of the lightingmodule seen in

FIG. 2.

FIG. 4 is a flowchart illustrating an example method for controlling thepower supplied to a lighting module based on the detection of anobstruction, according to an embodiment.

FIG. 5 depicts an example of internal hardware that may be used tocontain or implement the various processes and systems as described inthis disclosure.

DETAILED DESCRIPTION

As used in this document, the singular forms “a,” “an,” and “the”include plural references unless the context clearly dictates otherwise.Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art. As used in this document, the term “comprising” means“including, but not limited to.”

When used in this document, terms such as “top” and “bottom,” “upper”and “lower”, or “front” and “rear,” are not intended to have absoluteorientations but are instead intended to describe relative positions ofvarious components with respect to each other. For example, a firstcomponent may be an “upper” component and a second component may be a“lower” component when a light fixture is oriented in a first direction.The relative orientations of the components may be reversed, or thecomponents may be on the same plane, if the orientation of a lightfixture that contains the components is changed. The claims are intendedto include all orientations of a device containing such components.

In this document, the terms “lighting device,” “light fixture,”“luminaire” and “illumination device” are used interchangeably to referto a device that includes a source of optical radiation. Sources ofoptical radiation may include, for example, light emitting diodes(LEDs), light bulbs, ultraviolet light or infrared sources, or othersources of optical radiation. In the embodiments disclosed in thisdocument, the optical radiation emitted by the lighting devices includesvisible light. A lighting device will also include a housing, one ormore electrical components for conveying power from a power supply tothe device's optical radiation source, and optionally control circuitry.

In this document, the terms “controller” and “controller device” mean anelectronic device or system of devices containing a processor andconfigured to command or otherwise manage the operation of one or moreother devices. A controller will typically include a processing device,and it will also include or have access to a memory device that containsprogramming instructions configured to cause the controller's processorto manage operation of the connected device or devices.

In this document, the terms “memory” and “memory device” each refer to anon-transitory device on which computer-readable data, programminginstructions or both are stored. Except where specifically statedotherwise, the terms “memory” and “memory device” are intended toinclude single-device embodiments, embodiments in which multiple memorydevices together or collectively store a set of data or instructions, aswell as one or more individual sectors within such devices.

In this document, the terms “processor”, “processing device”,“processing circuit” refer to a hardware component of an electronicdevice (such as a controller) that is configured to execute programminginstructions. Except where specifically stated otherwise, the singularterm “processor” or “processing device” is intended to include bothsingle processing device embodiments and embodiments in which multipleprocessing devices together or collectively perform a process.

An “electronic device” refers to an electronic device having aprocessor, a memory device, and a communication interface forcommunicating with proximate and/or local devices. The memory willcontain or receive programming instructions that, when executed by theprocessor, will cause the electronic device to perform one or moreoperations according to the programming instructions. Examples ofelectronic devices include personal computers, servers, mainframes,virtual machines, containers, gaming systems, televisions, and portableelectronic devices such as smartphones, wearable virtual realitydevices, Internet-connected wearables such as smart watches and smarteyewear, personal digital assistants, tablet computers, laptopcomputers, media players and the like. Electronic devices also mayinclude appliances and other devices that can communicate in anInternet-of-things arrangement, such as smart thermostats, homecontroller devices, voice-activated digital home assistants, connectedlight bulbs and other devices. In a client-server arrangement, theclient device and the server are electronic devices, in which the servercontains instructions and/or data that the client device accesses viaone or more communications links in one or more communications networks.In a virtual machine arrangement, a server may be an electronic device,and each virtual machine or container may also be considered to be anelectronic device. In the discussion below, a client device, serverdevice, virtual machine or container may be referred to simply as a“device” for brevity. Additional elements that may be included inelectronic devices will be discussed below in the context of FIG. 5.

FIG. 1 illustrates one embodiment of an example lighting device 100 thatis configured to detect an obstruction on one or more of its components.As shown in FIG. 1, the lighting device 100 includes a housing 102 thatencases various components of a light fixture. The housing 102 includesan opening in which an optical radiation source such as any number oflighting modules 110 that include LEDs are included. Any number oflighting modules 110, such as one, two, three, four, five or more,sufficient to provide a high intensity LED device, may be positionedwithin the opening in any configuration. In various embodiments, alighting device may include multiple types of lighting modules. Forexample, a lighting device may include a first type of lighting modulehaving LEDs that are configured to selectably emit white light ofvarious color temperatures, along with a second type of lighting modulehaving LEDs that are configured to selectably emit light of variouscolors. The lighting modules 110 may include an optional opticalarrangement (interchangeably, “optics” or “optical assembly”) comprisingone or more optical elements, as will be described in more detail below.

The device's housing 102 may also include an optional heat sink 104 fordissipating heat that is generated by the LEDs of the lighting modules110. The heat sink 104 may be formed of aluminum and/or other metal,plastic or other material, and it may include any number of fins on theexter or increase its surface area that will contact a surroundingcooling medium (typically air). Thus, heat from the LEDs may be drawnaway from the lighting modules 110 and dissipated via the fins of theheat sink 104.

While the lighting modules 110 are positioned at one side of the housing102, the opposing side of the housing may include or be connected to apower supply (not shown here). The power supply may include a battery,solar panel, or circuitry to receive power from an external and/or otherinternal source, The external housing of the power supply also mayinclude fins to help dissipate heat from the power supply. Power wiringmay be positioned within the housing 102 to direct power from the powersupply to the LEDs.

The housing 102 also may hold electrical components such as a fixturecontroller and wiring and circuitry to supply power and/or controlsignals to the lighting modules 110, A fixture controller may be anexternal device or an integral device that includes various componentsof a lighting device's control circuitry (such as a processor and memorywith programming instructions, an application-specific integratedcircuit or a system-on-a-chip, a communications interface, etc.)configured to selectively control which LEDs in the lighting modules 110are to receive power, and to vary the power delivered to the LEDs bymethods such as pulse width modulation (PWM). Optionally, the housing102 may be attached to a support structure, such as a base or mountingyoke, optionally by one or more connectors.

FIG. 2 illustrates a top view of an example lighting module 110according to an embodiment, while FIG. 3 illustrates a cross sectionalview of the lighting module 110 along cutline 3-3 in FIG. 2.

Referring now to FIG. 2 and FIG. 3, the lighting device 100 shown inFIG. 1, for example, may have eight lighting modules 110. Each lightingmodule 110 may include a substrate 112 and one or more LEDs 113positioned on the substrate 112.

In certain embodiments, the substrate 112 may be a supporting structureconfigured to hold the LEDs 113 in place. For example, the substrate 112may be made of any support material (such as fiberglass, ceramic,silicon, or aluminum with conductive elements (such as traces, bars, orwires) placed thereon or therein to direct power, control signal, or thelike to the LEDs 113. The conductive elements may be copper, silver oranother conductive material and applied as conductive ink, wire, traces,or other materials to provide a conductive pathway, Optionally, thesubstrate 112 may include a portion that is a circuit board (not shownhere). Driver circuitry on the circuit board and/or a controller (e.g.,fixture controller) may deliver current, control signals, etc. to theLEDs 113 via one or more conductive elements on the substrate 112, suchas conductive lines, traces, bars or wires positioned on the substrate112. In certain embodiments, various conductors, electronic devices(e.g., sensors), etc. may also be mounted on the substrate 112. Forexample, a set of module-level conductors may be connected to thelighting module's power source and ground. Each module-level conductormay be connected to one of the conductive elements on the substrate 112.

The LEDs 113 may be arranged in one or more rows, matrices, concentricrings, or other arrangements with corresponding components supported inplace and/or spaced apart by supports. The lighting module 110 shown inFIG. 2, for example, may have twelve LEDs 113 positioned on thesubstrate 112 in two concentric rings. Alternatively, the LEDs 113 ineach lighting module 110 may be positioned in curved rows so that whenall lighting modules 110 are positioned within the opening, the LEDstructure (i.e., the lighting device 100 as a whole) may have concentricrings of LEDs 113.

The lighting module 110 may also include an optical assembly 111configured to control one or more optical properties (e.g., beam angle,direction, stray light, color fringing, etc.) of the light emitted bythe LEDs 113 and lighting module 110. In certain embodiments, theoptical assembly 111 may also protect the LEDs 113 of a lighting module110 from environmental elements such as, moisture, rain, dirt, excessivesunlight, or the like. The optical assembly 111 may include one or moreoptical elements. Examples of such optical elements may include, withoutlimitation, lenses, refractors, reflectors, lens covers, frosted beamoptics, and/or the like. The optical elements of an optical assembly 111may be made from a material, such as, for example and withoutlimitation, plastic, resin, silicone, optical silicone, metal, metalcoated plastic, acrylic, or the like. Furthermore, the optical assembly111 may have many shapes, such as, for example, round, square,rectangular, diamond, or the like.

As shown in FIG. 3, an LED 113 may be located under an optical assembly111 comprising a collimating lens 111(a). Optionally, a clear opticalcover 111(b) may be placed on top of the collimating lens 111(a) to sealand protect the lens and the LEDs from environmental elements. It willbe understood to those skilled in the art that the optical assembly 111illustrated in FIG. 3 is provided as an example, and any other opticalelements or their combination thereof may be included in the opticallens assembly 111 of the lighting module 110 without deviating from theprinciples of this disclosure. For example, the optical assembly 111 ofFIG. 3 may include a combination of a reflector and a refractorconfigured to provide collimation or other properties of light receivedfrom the LEDs 113.

A lighting module 110 may include identical optical assemblies 111.Alternatively, at least one of the optical assemblies 111 may bedifferent.

Each lighting module 110 may also include an obstruction sensor 115 formonitoring the conditions or properties of the optical assembly 111based on a pattern of radiation reflected by the optical assembly 111.For example, the obstruction detection sensor 115 may be configured toemit and capture reflected radiation (e.g., infrared (IR) light or nearIR light), and comparing the radiation reflected from the opticalassembly 111 to known patterns and sequences, in order to monitor and/ordetermine the conditions or properties of the optical assembly 111 inreal-time, as described below. Such conditions or properties of theoptical assembly 111 may be indicative of the presence of obstructionsand/or deformities on the optical assembly 111. In example embodiments,the obstruction sensor 115 may analyze the radiation reflected by theoptical assembly 111 to detect obstructions due to the presence ofelements or objects (e.g., dirt, debris, water, fog, bird droppings,frost, or other objects) and/or the formation of deformities (e.g.,cracks, pits, shape changes) on the optical assembly 111.

As discussed above, monitoring conditions or properties of the opticalassembly 111 or changes in the optical assembly 111 is important formaintaining a desired light output from each lighting module 110 as wellas the health of the lighting device 110 as a whole. The conditions orchanges in the optical assembly 111 may be monitored by analyzing theradiation reflected from the optical assembly 111 and comparing it toknown patterns and sequences. Specifically, obstructions and/ordeformities on the inner surface and/or the outer surface of the opticalassembly 111 may cause changes in the known patterns or sequences of thereflected radiation obtained from non-obstructed optical assembly and/orprovide patterns or sequences corresponding to a type of obstruction.Examples of obstructions or deformities on the inner surface of theoptical assembly 111 may include, without limitation, condensationcaused by humid air near the lighting module 110, dirt particleaccumulation, discoloration of an optical element (e.g., due tooverheating), warping, or the like. Examples of obstructions ordeformities on the outer surface of the optical assembly 111, mayinclude, without limitation, the accumulation of dust, dirt, or grime,the application of paint or stickers due to vandalism, the warping dueto overheating, discoloration of an optical element (i.e., the yellowingof polycarbonate materials), cracks due to accidental impacts fromsporting equipment, formation of pits, or the like. As discussed above,presence of obstructions and/or deformities on the optical assembly 111may lead to changes in the output light distribution from the lightingmodule 110 and/or excessive heating of the inside lighting module 110thus causing damage to one or more components of the lighting module 110(e.g., the LEDs 113 and the circuitry on the substrate 112).

In certain embodiments, the reflected radiation pattern may provideinformation about the conditions or properties of the optical assembly111, such as, for example, presence of an obstruction and/or a deformityon the optical assembly 111, the type of obstruction and/or deformity(dirt, water, warping, etc.); the degree of obstruction and/or deformity(e.g., amount of dirt, moisture, degree of warping, amount ofdiscoloration, size of a crack, etc.); location of obstruction and/ordeformity; or the like. For example, the obstruction sensor 115 maycompare the received reflected radiation pattern with known patternscorresponding to the type of obstruction and/or deformity, the degree ofobstruction and/or deformity, the location of obstruction and/ordeformity, etc.

The obstruction sensor 115 may include a transceiver assembly (notshown) and has a line-of-sight to at least one optical element of theoptical assembly 111 for transmitting radiation (e.g., IR radiation) tothe optical assembly 111, and receiving the reflected radiation. Theobstruction sensor 115 may also include a processor (not shown)configured to analyze the reflected radiation pattern to provideinformation about the conditions or properties of the optical assembly111. Alternatively and/or additionally, the processor may not beincluded in the obstruction sensor 115 and an external processor (e.g.,a processor of the lighting device 100) may receive data from theobstruction sensor 115 via a communications link for analysis. Theobstruction sensor 115 may also be connected to the power source and/orthe control circuit(s) (e.g., via traces or conductors) of the lightingmodule 110 to provide power and/or data communication to the obstructionsensor 115.

An example obstruction sensor 115 may include an IR sensor.

In certain embodiments, the obstruction sensor 115 may be mounted on thesubstrate 112 at a location that allows radiation emitted by theobstruction sensor to be at least partially reflected by an opticalelement of the optical assembly 111, and the reflected radiation to bereceived by the obstruction sensor 115 (i.e., within a line-of sight ofthe optical element). The position of the obstruction sensor 115 on thesubstrate 112 may be determined based on the field of view of theobstruction sensor 115 and/or the distance to the optical assembly 111to be monitored, and the optical assembly to be monitored by theobstruction sensor. For example, the obstruction sensor 115 may bepositioned centrally on the substrate 112 and/or, as shown in FIG. 2,positioned spaced a distance from the center to enable it to monitor theconditions of a portion of the optical assembly 111 that lies within the“field of view” of the obstruction sensor 115. The position shown inFIG. 2 is provided by way of example only and may be changed based on,without limitation, the field of view of the obstruction sensor 115,placement of one or more components inside the lighting module 110 whichmay block the field of view, or the like. Specifically, placement of theobstruction sensor 115 at other locations within the lighting module 110is within the scope of this disclosure. In certain embodiments, theobstruction sensor 115 may have dimensions that allow for mounting ofthe obstruction sensor 115 on the substrate 112 of a lighting module 110(e.g., approximately 1-5 mm² surface area and negligible thickness). Incertain embodiments, the obstruction sensor field of view may begenerally circular, and the size of the obstruction sensor 115 is suchthat it can be considered to be a point source/detector. The diameter ofthe circular field of view may increase with distance from the source todefine a cone whose apex is at the center of the obstruction sensor 115.The conditions monitored by an obstruction sensor may correspond to anaverage of conditions of all objects in the field of view of theobstruction sensor 115. Example conical field of views for theobstruction sensor 115 of the current disclosure may be about 10° toabout 90°, about 15° to about 75°, about 25° to about 65°, or about 35°to about 65°.

While the current disclosure describes the obstruction sensor 115 asbeing mounted on the substrate 112 of the lighting module 110, thedisclosure is not so limiting. For example, the obstruction sensor 115may be mounted on a different supporting structure other than thesubstrate 112 for monitoring the conditions of the optical assembly 111.

In certain embodiments, a lighting module 110 may include one or moreobstruction sensors 115. Optionally, a lighting module 110 may notinclude an obstruction sensor 115, and an obstruction sensor 115 locatedoutside the lighting module 110 (e.g., included in another lightingmodule, and/or in an area shared by the lighting modules of the lightingdevice 100) may be configured to monitor the properties or conditions ofan optical assembly 111 of that lighting module 110. The obstructionsensors 115 may likewise by spaced apart evenly or placed randomly inthe lighting modules 110 of a lighting device 100.

Some minor obstructions may cause further major obstructions such as,for example, a minor accumulation of dust may cause the internaltemperature of the lighting module 110 to increase (i.e., overheat),thus further causing a warping of the optical assembly 111, whichcreates even more overheating that causes yet even further major damageby cracking the optical assembly 111. Minor obstructions, such as dust,dirt and grime, may be easily wiped off during normal preventivemaintenance, whereas major obstructions, such as yellowing, warping, andcracks require costly replacement of the optical assembly 111 or thecomplete lighting module 110. As such, the obstruction sensor 115 of thecurrent disclosure may be used for continuous monitoring of the opticalassembly 111 of a lighting module 110, and may be configured to cause aprocessor to provide alerts, prompts, perform automatic restorativeactions (e.g., corrective or preventive maintenance action), and/orinstructions to prevent and/or reduce severity of damage to a lightingmodule 110. For example, if it is determined that the amount ofaccumulation of dirt/debris (i.e., obstruction or deformity) is over athreshold (as determined by analyzing the reflection pattern), a promptor an alert may be provided to a user to clean and/or repair the opticalassembly 111. Alternatively and/or additionally, the power delivered tothe LEDs may be controlled (e.g., switched off or reduced) to preventfurther damage to the lighting module 110 until the dirt and debris(i.e., obstruction and/or deformity) has been removed or repaired fromthe optical assembly 111.

In one or more embodiments, the threshold may be determined based on oneor more of the following: the type of LEDs, material of the opticalelements of the optical assembly, material of other components of thelighting nodule, ambient conditions (e.g., outside temperature,pressure, humidity, internal temperature, etc.), type of use of thelighting device (e.g., constant use v. occasional use), efficiency ofthe heat sink, or the like.

In one or more embodiments, the obstruction sensor 115 may be an activeinfrared (IR) sensor that transmits and receives IR radiation, forexample, over a 180° hemisphere substantially normal to the substrate112. The IR obstruction sensor 115 may convert the reflected radiationto a proportional signal (e.g., current or voltage) that is indicativeof one or more properties of the optical assembly 111 using a signalprocessing circuit included in the IR obstruction sensor 115 (and/orsend the data to an external processing device for analysis). When anobstruction or deformity occurs, the reflected IR beam collected by anIR obstruction sensor 115 changes in pattern compared to when there isno obstruction or deformity in the optical assembly 111.

As discussed above, data collected by an obstruction sensor 115 may beprocessed by a processor included in the obstruction sensor 115, and/ormay be transmitted to an external processor for analysis (e.g., fixturecontroller and/or module level controller of the lighting module 110).Optionally, the obstruction sensor 115 may at least partially processthe collected data and transmit such processed data to the externalprocessor for further analysis and/or appropriate action. The controllerand the obstruction sensor 115 may communicate with each other using anysuitable communication protocol such as, without limitation, I2C. Thecontroller may in turn control current delivered to the LEDs 113 of thelighting module 110 based on the received data. For example, thecontroller may throttle back power/current supplied to one or more LEDs113 of the lighting module 110 if it is determined that the opticalassembly 111 has an obstruction level and/or deformity that is greaterthan a threshold, The controller may throttle back power supplied to oneor more LEDs 113 of the lighting module 110, for example, by decreasingor turning off current supplied to the LEDs 113, by decreasing pulsewidth modulation (PWM), or a combination thereof. In PWM, an oscillatingoutput from the controller repeatedly turns the LEDs 113 on and offbased by applying a pulsed voltage. Each pulse is of a constant voltagelevel, and the controller varies the width of each pulse and/or thespace between each pulse. When a pulse is active, the LEDs 113 may beturned on, and when the pulses are inactive the LEDs 113 may be turnedoff. If the duty cycle of the “on” state is 50%, then the LEDs 113 maybe on during 50% of the overall cycle of the control pulses. Thecontroller may dim the LEDs 113 by reducing the duty cycle andeffectively extending the time period between each “on” pulse, so thatthe LEDs are off more than they are on. Alternatively, the controllermay decrease the brightness of the LEDs 113 by decreasing the dutycycle.

In certain embodiments, the controller may monitor the received data todetermine a rate of change in conditions (i.e., rate of increase inobstruction and/or deformity) of the optical assembly 111. Rate ofincrease in the obstruction and/or deformity of the optical assembly 111that is more than a threshold may be indicative of other problems in thelighting module 110 (e.g., a leak in the seal of the lighting device ormodule, excessive accumulation of debris, change in orientation,breakage or other types of damage, or the like). The controller maycreate and output an alert for a user based upon such determination thatincludes information about the identified problems.

FIG. 4 illustrates an example flowchart in accordance with variousembodiments illustrating and describing a method 400 of monitoring theclarity of an optical assembly 111 on a lighting module 110 andcontrolling power supplied to one or more LEDs 113 of the lightingmodule 110. While the method 400 is described for the sake ofconvenience and not with an intent of limiting the disclosure ascomprising a series and/or a number of steps, it is to be understoodthat the process does not need to be performed as a series of stepsand/or the steps do not need to be performed in the order shown anddescribed with respect to FIG. 4 but the process may be integratedand/or one or more steps may be performed together, simultaneously, orthe steps may be performed in the order disclosed or in an alternateorder.

At 402, a controller may receive data relating to the real-timeconditions of an optical assembly from one or more obstruction sensor(s)included in a lighting module. The controller may analyze (404) thereceived data to determine whether there exists a threshold level ofobstructions and/or a deformities in the optical assembly. Thecontroller may determine the threshold by accessing a rule set thatincludes threshold for various parameters such as, without limitation,ambient conditions, material of manufacture, type of LEDs, use of LEDs,efficiency of the heat sink, type of damage to be prevented, etc. (asdiscussed above).

If it is determined that there exists a threshold level of obstructionsand/or a deformities in the optical assembly, the controller may (406)perform a restorative action (to prevent damage to the lighting deviceand/or cause repair or cleaning of the optical assembly). For example,the controller may provide an alert to a user (e.g., via a mobile deviceor display) including information about the obstruction and/or deformity(e.g., type of obstruction or deformity, level of obstruction ordeformity, position of obstruction or deformity, or the like).Optionally, the controller may also provide instructions to a usercorresponding to potential corrective actions (e.g., clean the opticalassembly, replace the optical assembly, turn off power, etc.).Alternatively and/or additionally, the controller may itself initiatesuch corrective action. For example, the controller may selectivelythrottle back (406) power supplied to one or more LEDs of the lightingmodule. For example, the controller may throttle back power supplied toone or more LEDs of the lighting module by reducing current supplied tothe LEDs or by reducing PWM. In certain embodiments, the controller mayreduce the power supplied to one or more LEDs while maintaining adesired output of the lighting module (and/or lighting device) at asubstantially constant level by, for example, turning on other LEDsand/or other lighting modules, increasing power to other LEDs,increasing PWM for other LEDs, or lighting modules of the lightingdevice.

As such, controlling the power supplied to the plurality of lightsources dependent upon the detection of an obstruction of the lightingmodule can extend the useful life of the lighting module. For example,the useful life can be extended by limiting the possibility for heatrelated damage by preventing the temperature to rise above a thresholdtemperature sufficient to cause damage to the internal components of thelighting module.

FIG. 5 is a block diagram of hardware that may be including in any ofthe electronic devices described above, such as a lighting device 100,an obstruction sensor 115, or device controller of the lighting device100. A bus 500 serves as an information highway interconnecting theother illustrated components of the hardware. The bus may be a physicalconnection between elements of the system, or a wired or wirelesscommunication system via which various elements of the system sharedata. Processor 505 is a processing device of the system performingcalculations and logic operations required to execute a program.Processor 505, alone or in conjunction with one or more of the otherelements disclosed in FIG. 5, is an example of a processing device,computing device or processor as such terms are used within thisdisclosure. The processing device 505 may be a physical processingdevice, a virtual device contained within another processing device, ora container included within a processing device. If the electronicdevice is a lighting device 100, processor 505 may be a component of afixture controller, and the lighting device 100 would also include apower supply and optical radiation source (e.g., at least one LED) asdiscussed above.

A memory device 510 is a hardware element or segment of a hardwareelement on which programming instructions, data, or both may be stored.An optional display interface 530 may permit information to be displayedon the display 535 in audio, visual, graphic or alphanumeric format.Communication with external devices, such as a printing device, mayoccur using various communication interfaces 550, such as acommunication port, antenna, or near-field or short-range transceiver. Acommunication interface 550 may be communicatively connected to acommunication network, such as the Internet or an intranet.

The hardware may also include a user input interface 555 which allowsfor receipt of data from input devices such as a keyboard or keypad 550,or other input device 555 such as a mouse, a touchpad, a touch screen, aremote control, a pointing device, a video input device and/or amicrophone. Data also may be received from an image capturing device 520such as a digital camera or video camera. A positional sensor 560 and/ormotion sensor 570 may be included to detect position and movement of thedevice. Examples of motion sensors 570 include gyroscopes oraccelerometers. Examples of positional sensors 560 such as a globalpositioning system (GPS) sensor device that receives positional datafrom an external GPS network.

The features and functions described above, as well as alternatives, maybe combined into many other systems or applications. Various presentlyunforeseen or unanticipated alternatives, modifications, variations orimprovements may be made by those skilled in the art, each of which isalso intended to be encompassed by the disclosed embodiments.

1. A lighting device comprising: an optical assembly; an obstructionsensor configured to receive radiation reflected by the opticalassembly; a processor; and a non-transitory computer-readable mediumcomprising programming instructions that when executed by the processor,cause the processor to: receive, from the obstruction sensor,information corresponding to the radiation reflected by the opticalassembly; and compare the received information to a plurality of knownreflection patterns associated with one or more properties of theoptical assembly to determine a property of the optical assembly.
 2. Thelighting device of claim 1, wherein the obstruction sensor comprises aninfrared (IR) sensor and the reflected radiation comprises IR radiation.3. The lighting device of claim 1, wherein the obstruction sensor isfurther configured to transmit radiation towards the optical assembly.4. The lighting device of claim 3, wherein the obstruction sensor ismounted in the lighting device in a location that allows radiationtransmitted by the obstruction sensor to be at least partially reflectedby an optical element of the optical assembly.
 5. The lighting device ofclaim 4, wherein the obstruction sensor is mounted on a substrate of thelighting device.
 6. The lighting device of claim 1, wherein the propertycomprises a presence of at least a threshold level of an obstruction ora deformity on the optical assembly; and the lighting device furthercomprises programming instructions that when executed by the processor,cause the processor to, in response to determining the presence of atleast the threshold level of the obstruction or the deformity on theoptical assembly, perform a restorative action.
 7. The lighting deviceof claim 6, wherein the restorative action comprises providing an alertto a user, the alert comprising at least one of the following:instructions to repair the obstruction or the deformity; instructions tocontrol power delivered to a light source included in the lightingdevice; or information relating to the obstruction or the deformity. 8.The lighting device of claim 7, wherein the programming instructions tocontrol the power delivered to the light source comprise instructions toreduce power delivered to the light source while maintaining a constantillumination output by the lighting device.
 9. The lighting device ofclaim 6, wherein the restorative action comprises controlling powerdelivered to the light source.
 10. The lighting device of claim 6,wherein the obstruction or the deformity comprises at least one of thefollowing on an inside or an outside of the optical assembly:accumulation of debris, accumulation of dirt, accumulation of water,accumulation of moisture, change in color, change in shape, breakage,accumulation of foreign materials, or formation of pits.
 11. Thelighting device of claim 6, wherein the threshold level is determinedbased on at least one of the following: a type of a light sourceincluded in the lighting device, a material of the optical assembly, amaterial of other components of the lighting device, one or more ambientconditions, a type of use of the lighting device, or efficiency of aheat sink associated with the lighting device.
 12. The lighting deviceof claim 6, further comprising programming instructions that cause theprocessor to analyze the received information to determine, about theobstruction or the deformity, at least one of the following: a type ofobstruction or deformity, a level of obstruction or deformity, or alocation of obstruction or deformity on the optical assembly.
 13. Thelighting device of claim 1, further comprising programming instructionsconfigured to cause the processor to: analyze the received informationto determine a rate of change of the property of the optical assembly;analyze the rate of change to determine whether the lighting deviceincludes a problem; and provide an alert to a user, wherein the alertincludes information about the problem.
 14. The lighting device of claim1, wherein the lighting device further comprises a light source mountedunder the optical assembly.
 15. A method for determining a property ofan optical assembly of a lighting device, the method comprising, by aprocessor: receiving, from an obstruction detection sensor mountedinside the lighting device, information corresponding to radiationreflected by the optical assembly; and comparing the receivedinformation to a plurality of known reflection patterns associated withone or more properties of the optical assembly to determine the propertyof the optical assembly.
 16. The method of claim 15, wherein theobstruction sensor comprises an infrared (IR) sensor.
 17. The method ofclaim 15, wherein the property comprises a presence of at least athreshold level of an obstruction or a deformity on the opticalassembly, and the method further comprises determining the presence ofat least the threshold level of the obstruction or the deformity on theoptical assembly, perform a restorative action.
 18. The method of claim17, wherein the restorative action comprises providing an alert to auser, the alert comprising at least one of the following: instructionsto repair the obstruction or the deformity; instructions to controlpower delivered to a light source of the lighting device; or informationrelating to the obstruction or the deformity.
 19. The method of claim18, wherein the restorative action comprises controlling power deliveredto the light source.
 20. The method of claim 17, wherein the thresholdlevel is determined based on at least one of the following: a type ofthe light source, a material of the optical. assembly, a material ofother components of the lighting device, one or more ambient conditions,a type of use of the lighting device, or efficiency of a heat sinkassociated with the lighting device.
 21. The method of claim 15, furthercomprising: analyzing the received information to determine a rate ofchange of the property of the optical assembly; analyzing the rate ofchange to determine whether the lighting device includes a problem; andproviding an alert to a user, wherein the alert includes informationabout the problem.